A high-frequency waveguide used as a transmission path for high-frequency energy is constituted by combining first and second waveguide constituting bodies.
More specifically, first and second waveguide constituting bodies each provided with a groove are integrated in a state in which the openings of the grooves are aligned, which constitutes a high-frequency waveguide. A prior publication that is similar to this is Patent Literature 1 (Japanese Laid-Open Patent Application 2004-48486).